Even if you keep your cage clean, there's still a lot of bacteria that builds up on a daily basis.. Moisture/Shed-Skin/Excrement is the culprit.
Your cham could have rubbed up against something that broke the skin, and then the bacteria hits an open wound.. whammo.
I am just totally guessing on this on.
Hit the tail with some neosporin.. If it the sick skin doesn't get better, or gets worse, time for a vet. (I would have a vet look at it anyway, just to be safe)
I'm glad you are looking forward to the Silkies.. I am too.
It's always fun solving a few problems now and again.
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Joe
- www.silkwormfarm.com